In a release on Thursday night, the Marine and Freshwater Research Institute stated that genetic testing confirms that "the whale in question that was caught on July 7th was a hybrid of a fin whale father and a blue whale mother".

The claim comes after an international group of marine scientists and whale experts wrote to the Icelandic Government on July 14, calling for whaling fleets in Iceland to be grounded until the identity of the whale was established.

While many anti-whaling activist groups and experts had identified the whale from photos as a blue whale, the CEO of the whaling company at the centre of the controversy, Kristjan Loftsson, last week told the ABC he was sure it was a hybrid.

"I've seen some of the other hybrids we've had in the past, and this looked like [those]," he said.